Abstract
Annealing technologies are recently becoming an indispensable process for developing high quality bulk III-V materials to control various defects in the materials. Arsenic precipitates in undoped bulk GaAs material can be reduced by high temperature wafer-annealing because of stoichiometry controllability. It was recently found that undoped thick epitaxial conductive GaAs layers can be converted to semi-insulating slate by wafer-annealing at medium temperature's. Undoped semi-insulating InP was found to be prepared by wafer annealing. Undoped GaP has also been found to become semi-insulating by wafer-annealing. In the present paper, the recent developments of bulk III-V materials are reviewed focusing on the effect of various annealing technologies from the viewpoint of defect control.